Medical devices are becoming increasingly complex in function and geometry. It has been recognized that imparting desirable properties to the surface of medical devices, in particular small implantable medical devices, by coating the surface of the device with one or more compounds can enhance the function and effectiveness of the medical device. Traditional coating methods, such as dip coating, are often undesirable for coating these complex geometries since coating solution may get entrapped in the device structure. This entrapped solution may cause webbing or bridging of the coating solution and may hinder the device from functioning properly.
Other techniques, such as spray coating, have also been used to apply coating material to various devices, including medical devices. However, some methods of spray coating can also be problematic. In particular, devices may stick to components of the coating apparatus. Sticking may cause problems manipulating the devices and may result in an increased defect rate. Further, devices to be coated may have or pick up a static charge. A static charge may also lead to problems in manipulating the devices and may also result in an increased defect rate. Problems with sticking and static charges can be greater in the context of stents that are small in size.
Accordingly, there is a need for methods and devices for overcoming problems associated with spray coating procedures.